Optical attenuation design for high energy laser beam on-line diagnostic system

Optical attenuation coefficient as low as 10-4~10-3 is needed in the application of the high energy laser beam on-line diagnostic system based on a scanning circular reflector. For the low linear saturation threshold of photoelectric detector, a new and reliable method used in diagnostic system is introduced to attenuate high energy laser power density using multilayer dielectric coating. The principle of the beam sampling and attenuation is presented, and transmission coefficient characteristics of the coating are investigated under laser incidence angle of 0°~15° and power density of 1~1 000 W/cm2. At last, the feasibility of the method is proved by experiments.